feat(ags-v3): desktop adaptation — ultrawide scaling, brain power panel, system stats

- Scaling 16px base pour ultrawide 3440x1440
- Bar: CPU/RAM/GPU visible, media single player (skip playerctld), network tooltip LAN/WAN IPv4
- Volume: class module pour sizing cohérent
- Battery: désactivé (PC fixe)
- Clock: tooltip calendrier + uptime
- BrainPower: panel enrichi (focus, session, intentions, todos, repos git, derniers commits)
- App: BrainPower sur moniteur principal uniquement
- Heartbeat: Layer.TOP pour compatibilité COSMIC

ags-v3/style.scss

@@ -4,7 +4,7 @@
 
 * {
   font-family: $font;
-  font-size: 13px;
+  font-size: 16px;
   font-weight: bold;
 }
 
@@ -96,10 +96,32 @@ window.BrainPower {
     padding: 4px 0 4px 16px;
   }
 
-  .brain-terminal-placeholder {
+  .brain-version {
     color: $muted;
-    font-size: 11px;
-    font-style: italic;
-    padding: 8px 0 4px 16px;
+    font-size: 12px;
+    font-weight: normal;
+  }
+
+  .brain-intentions-list {
+    color: $mitsuri;
+    font-size: 13px;
+    font-weight: normal;
+    padding: 4px 0 4px 16px;
+  }
+
+  .brain-repos-status {
+    color: $subtext1;
+    font-size: 13px;
+    font-weight: normal;
+    font-family: "Maple Mono NF", monospace;
+    padding: 4px 0 4px 16px;
+  }
+
+  .brain-commits-list {
+    color: $subtext0;
+    font-size: 12px;
+    font-weight: normal;
+    font-family: "Maple Mono NF", monospace;
+    padding: 4px 0 4px 16px;
   }
 }